In response to Nigel's comments on an earlier thread (http://goweros.blogspot.com/2010/02/velvet-scoter-off-crymlyn-burrows-beach.html), I saw my first Buff-tailed Bumble-bee (Bombus terrestris) queen of the year on 16th Feb at Parc-y-Werin, Gorseinon. I'll certainly be keeping an eye open in the race to spot the first Bombus hypnorum for the west of the county! Excellent photos of this distinctive species can be seen at http://www.flickr.com/photos/tristanba/3511293282/ though I guess it's not one of the earlier species to emerge?
Thanks for the link to NHM website - this looks very useful.
http://www.nhm.ac.uk/research-curation/research/projects/bombus/